What are the functions of photochromic lenses and polarized lenses?

When buying glasses, many people are confused about photochromic lenses and polarized lenses.

Photochromic lenses, also known as "photosensitive lenses".

According to the principle of reversible reaction of light and color interchange, the lens can quickly darken under the irradiation of light and ultraviolet rays, block strong light and absorb ultraviolet rays, and have a neutral absorption of visible light; when returned to a dark place, it can quickly restore the colorless and transparent state, ensuring the lens of light transmittance.

Polarized light can be divided into three types, namely linear polarized light, elliptical polarized light and circular polarized light. Generally, the so-called polarized light refers to linearly polarized light, also known as plane polarized light.

The vibration of this light wave is fixed along a specific direction, the propagation path in space is a sinusoidal curve, and the projection on the plane perpendicular to the propagation direction is a straight line. When passing through the polarizing filter lens, it is filtered out by the louver structure of the black crystal, and the remaining useful vertical light enters the eyes, so as to achieve the purpose of blocking reflected light, and the feeling is comfortable and clear.

Polarized lenses are generally used to make sunglasses. No matter indoors or outdoors, its color is fixed (mostly polarized gray or polarized green, and there are also various colorful polarizers), which can organize light and effectively block strong light. glare.

different usage scenarios
Photochromic lenses are suitable for both indoor and outdoor use to prevent damage to eyes from sunlight, ultraviolet light, and glare.

In life, sunlight shines from all directions. When it hits an object, the light will be reflected again to form two kinds of light, horizontal and vertical. Horizontal light will cause dazzling random reflections. Polarized glasses can filter out these reflections. Therefore, it is suitable for driving and fishing, but not suitable for wearing indoors or watching electronic screens.